The post-election deal, between a dogmatic and narrow sect in the grips of a 17th-century mindset and the DUP, isn't a full-scale plighting of troths. It's more of a fling, for confidence and supply, between the Nasty Party and their Ulster brethren – devotees of the summer's glorious twelfths, when they have fun socking it to grouse (August) and nationalists (July). Each party remains hostage to its own contradictions. The Tories' lie between their laissez-faire ideologue Brexiters, whose holy of holies is free trade, and little Englander nativists, miffed that the wogs now start before Calais. The DUP's voter base, like everyone in Northern Ireland, depends on open borders with the republic, but its ideology covets a Brexit yet more rejectionist than that of many a gin-sozzled Tory backwoodsman.

That Theresa May has had to flop before the dinosaur-deniers attests to her feeble and feckless post-election state. There is a pattern: an enfeebled prime minister caving to the nationalist right. Commentators who harp on Labour's having lost the last three elections ignore the Tories' failure to win them decisively. David Cameron was spooked by Ukip, so to win in 2015 he offered an EU referendum. He blew that, partly because he couldn't get his Euro-septics behind him. After he went, May had to go full-throttle for Leave to buy Brexiter support. She then called another election, which she blew; now she's had to reach for the bowler hats. Jean-Claude Juncker and Michel Barnier at the EU must be chuckling all the way up La Manche, as the UK offers would-be Nexiters and Frexiters the spectacle of a country whirling out of EU orbit.

For now, the DUP have their moment in the sun. They’ve bagged an extra £1 billion for Northern Ireland – over two years, it's said, which presumably is how long the deal is expected to last. In some ways the DUP has reined in the nastiness, by blocking the scrapping of the pension triple lock and winter fuel allowance. They've also got May to underwrite the Nato-approved 2 per cent of GDP on defence. They haven’t got everything they wanted. The one thing that greens the DUP eye as it gazes across the border is the Republic's 12.5 per cent corporation tax rate, which Arlene Foster would like to bring north; since the crash, Dublin has coined it by hosting such well-loved paragons of footloose international capital as Google, Facebook, eBay and Hewlett-Packard. Previous haggling foundered on Westminster's insistence that a corporation tax cut would have to be linked to a cut in the block grant.

Like others, May's predecessor John Major has already warned of the risks of a deal that overtly sectarianises the UK government. That won't come as news to nationalists familiar with the British army Force Research Unit, a covert outfit co-ordinating with loyalist paramilitaries during the Troubles. Even before this month's election, Stormont faced the prospect of direct rule from London again (the clock runs down on 29 June). Virtually everyone wants open borders in Ireland, but that breaches Brexiters' fortress Britain fantasy. Has May been DUPed? As Chris Patten said over the weekend, since the Orangepeople want Corbyn less than May does, she could probably have hung tough, or simply ignored them. And the whole deal – a few sides of large-print A4 – has taken more than two weeks to negotiate.